different platforms, with the intention of solving problems once in a
generic framework which everyone can use.

Signed-off-by: Hiroshi DOYU <hdoyu@nvidia.com>
Cc: Hiro Sugawara <hsugawara@nvidia.com>
Cc: Krishna Reddy <vdumpa@nvidia.com>
---
 arch/arm/mach-tegra/include/mach/iovmm.h |  283 +++++++++
 drivers/iommu/Kconfig                    |    6 +
 drivers/iommu/Makefile                   |    1 +
 drivers/iommu/tegra-iovmm.c              |  936 ++++++++++++++++++++++++++++++
 4 files changed, 1226 insertions(+), 0 deletions(-)
 create mode 100644 arch/arm/mach-tegra/include/mach/iovmm.h
 create mode 100644 drivers/iommu/tegra-iovmm.c

diff --git a/arch/arm/mach-tegra/include/mach/iovmm.h b/arch/arm/mach-tegra/include/mach/iovmm.h
new file mode 100644
index 0000000..6fd0bb6
--- /dev/null
+++ b/arch/arm/mach-tegra/include/mach/iovmm.h
@@ -0,0 +1,283 @@
+/*
+ * Copyright (c) 2010-2011, NVIDIA Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed i the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#include <linux/list.h>
+#include <linux/platform_device.h>
+#include <linux/miscdevice.h>
+#include <linux/rbtree.h>
+#include <linux/rwsem.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#ifndef _MACH_TEGRA_IOVMM_H_
+#define _MACH_TEGRA_IOVMM_H_
+
+typedef u32 tegra_iovmm_addr_t;
+
+struct tegra_iovmm_device_ops;
+
+/* each I/O virtual memory manager unit should register a device with
+ * the iovmm system
+ */
+struct tegra_iovmm_device {
+	struct tegra_iovmm_device_ops	*ops;
+	const char			*name;
+	struct list_head		list;
+	int				pgsize_bits;
+};
+
+/* tegra_iovmm_domain serves a purpose analagous to mm_struct as defined in
+ * <linux/mm_types.h> - it defines a virtual address space within which
+ * tegra_iovmm_areas can be created.
+ */
+struct tegra_iovmm_domain {
+	atomic_t		clients;
+	atomic_t		locks;
+	spinlock_t		block_lock;
+	unsigned long		flags;
+	wait_queue_head_t	delay_lock;  /* when lock_client fails */
+	struct rw_semaphore	map_lock;
+	struct rb_root		all_blocks;  /* ordered by address */
+	struct rb_root		free_blocks; /* ordered by size */
+	struct tegra_iovmm_device *dev;
+};
+
+/* tegra_iovmm_client is analagous to an individual task in the task group
+ * which owns an mm_struct.
+ */
+
+struct iovmm_share_group;
+
+struct tegra_iovmm_client {
+	const char			*name;
+	unsigned long			flags;
+	struct iovmm_share_group	*group;
+	struct tegra_iovmm_domain	*domain;
+	struct miscdevice		*misc_dev;
+	struct list_head		list;
+};
+
+/* tegra_iovmm_area serves a purpose analagous to vm_area_struct as defined
+ * in <linux/mm_types.h> - it defines a virtual memory area which can be
+ * mapped to physical memory by a client-provided mapping function. */
+
+struct tegra_iovmm_area {
+	struct tegra_iovmm_domain	*domain;
+	tegra_iovmm_addr_t		iovm_start;
+	size_t				iovm_length;
+	pgprot_t			pgprot;
+	struct tegra_iovmm_area_ops	*ops;
+};
+
+struct tegra_iovmm_device_ops {
+	/* maps a VMA using the page residency functions provided by the VMA */
+	int (*map)(struct tegra_iovmm_domain *domain,
+		struct tegra_iovmm_area *io_vma);
+	/* marks all PTEs in a VMA as invalid; decommits the virtual addres
+	 * space (potentially freeing PDEs when decommit is true.) */
+	void (*unmap)(struct tegra_iovmm_domain *domain,
+		struct tegra_iovmm_area *io_vma, bool decommit);
+	void (*map_pfn)(struct tegra_iovmm_domain *domain,
+		struct tegra_iovmm_area *io_vma,
+		tegra_iovmm_addr_t offs, unsigned long pfn);
+	/* ensures that a domain is resident in the hardware's mapping region
+	 * so that it may be used by a client */
+	int (*lock_domain)(struct tegra_iovmm_domain *domain,
+		struct tegra_iovmm_client *client);
+	void (*unlock_domain)(struct tegra_iovmm_domain *domain,
+		struct tegra_iovmm_client *client);
+	/* allocates a vmm_domain for the specified client; may return the same
+	 * domain for multiple clients */
+	struct tegra_iovmm_domain* (*alloc_domain)(
+		struct tegra_iovmm_device *dev,
+		struct tegra_iovmm_client *client);
+	void (*free_domain)(struct tegra_iovmm_domain *domain,
+		struct tegra_iovmm_client *client);
+	int (*suspend)(struct tegra_iovmm_device *dev);
+	void (*resume)(struct tegra_iovmm_device *dev);
+};
+
+struct tegra_iovmm_area_ops {
+	/* ensures that the page of data starting at the specified offset
+	 * from the start of the iovma is resident and pinned for use by
+	 * DMA, returns the system pfn, or an invalid pfn if the
+	 * operation fails. */
+	unsigned long (*lock_makeresident)(struct tegra_iovmm_area *area,
+		tegra_iovmm_addr_t offs);
+	/* called when the page is unmapped from the I/O VMA */
+	void (*release)(struct tegra_iovmm_area *area, tegra_iovmm_addr_t offs);
+};
+
+#ifdef CONFIG_TEGRA_IOVMM
+/* called by clients to allocate an I/O VMM client mapping context which
+ * will be shared by all clients in the same share_group */
+struct tegra_iovmm_client *tegra_iovmm_alloc_client(const char *name,
+	const char *share_group, struct miscdevice *misc_dev);
+
+size_t tegra_iovmm_get_vm_size(struct tegra_iovmm_client *client);
+
+void tegra_iovmm_free_client(struct tegra_iovmm_client *client);
+
+/* called by clients to ensure that their mapping context is resident
+ * before performing any DMA operations addressing I/O VMM regions.
+ * client_lock may return -EINTR. */
+int tegra_iovmm_client_lock(struct tegra_iovmm_client *client);
+int tegra_iovmm_client_trylock(struct tegra_iovmm_client *client);
+
+/* called by clients after DMA operations are complete */
+void tegra_iovmm_client_unlock(struct tegra_iovmm_client *client);
+
+/* called by clients to allocate a new iovmm_area and reserve I/O virtual
+ * address space for it. if ops is NULL, clients should subsequently call
+ * tegra_iovmm_vm_map_pages and/or tegra_iovmm_vm_insert_pfn to explicitly
+ * map the I/O virtual address to an OS-allocated page or physical address,
+ * respectively. VM operations may be called before this call returns */
+struct tegra_iovmm_area *tegra_iovmm_create_vm(
+	struct tegra_iovmm_client *client, struct tegra_iovmm_area_ops *ops,
+	size_t size, size_t align, pgprot_t pgprot, unsigned long iovm_start);
+
+/* called by clients to "zap" an iovmm_area, and replace all mappings
+ * in it with invalid ones, without freeing the virtual address range */
+void tegra_iovmm_zap_vm(struct tegra_iovmm_area *vm);
+
+/* after zapping a demand-loaded iovmm_area, the client should unzap it
+ * to allow the VMM device to remap the page range. */
+void tegra_iovmm_unzap_vm(struct tegra_iovmm_area *vm);
+
+/* called by clients to return an iovmm_area to the free pool for the domain */
+void tegra_iovmm_free_vm(struct tegra_iovmm_area *vm);
+
+/* returns size of largest free iovm block */
+size_t tegra_iovmm_get_max_free(struct tegra_iovmm_client *client);
+
+/* called by client software to map the page-aligned I/O address vaddr to
+ * a specific physical address pfn. I/O VMA should have been created with
+ * a NULL tegra_iovmm_area_ops structure. */
+void tegra_iovmm_vm_insert_pfn(struct tegra_iovmm_area *area,
+	tegra_iovmm_addr_t vaddr, unsigned long pfn);
+
+/* called by clients to return the iovmm_area containing addr, or NULL if
+ * addr has not been allocated. caller should call tegra_iovmm_put_area when
+ * finished using the returned pointer */
+struct tegra_iovmm_area *tegra_iovmm_find_area_get(
+	struct tegra_iovmm_client *client, tegra_iovmm_addr_t addr);
+
+struct tegra_iovmm_area *tegra_iovmm_area_get(struct tegra_iovmm_area *vm);
+void tegra_iovmm_area_put(struct tegra_iovmm_area *vm);
+
+/* called by drivers to initialize a tegra_iovmm_domain structure */
+int tegra_iovmm_domain_init(struct tegra_iovmm_domain *domain,
+	struct tegra_iovmm_device *dev, tegra_iovmm_addr_t start,
+	tegra_iovmm_addr_t end);
+
+/* called by drivers to register an I/O VMM device with the system */
+int tegra_iovmm_register(struct tegra_iovmm_device *dev);
+
+/* called by drivers to remove an I/O VMM device from the system */
+int tegra_iovmm_unregister(struct tegra_iovmm_device *dev);
+
+#else /* CONFIG_TEGRA_IOVMM */
+
+static inline struct tegra_iovmm_client *tegra_iovmm_alloc_client(
+	const char *name, const char *share_group, struct miscdevice *misc_dev)
+{
+	return NULL;
+}
+
+static inline size_t tegra_iovmm_get_vm_size(struct tegra_iovmm_client *client)
+{
+	return 0;
+}
+
+static inline void tegra_iovmm_free_client(struct tegra_iovmm_client *client)
+{}
+
+static inline int tegra_iovmm_client_lock(struct tegra_iovmm_client *client)
+{
+	return 0;
+}
+
+static inline int tegra_iovmm_client_trylock(struct tegra_iovmm_client *client)
+{
+	return 0;
+}
+
+static inline void tegra_iovmm_client_unlock(struct tegra_iovmm_client *client)
+{}
+
+static inline struct tegra_iovmm_area *tegra_iovmm_create_vm(
+	struct tegra_iovmm_client *client, struct tegra_iovmm_area_ops *ops,
+	size_t size, size_t align, pgprot_t pgprot, unsigned long iovm_start)
+{
+	return NULL;
+}
+
+static inline void tegra_iovmm_zap_vm(struct tegra_iovmm_area *vm) { }
+
+static inline void tegra_iovmm_unzap_vm(struct tegra_iovmm_area *vm) { }
+
+static inline void tegra_iovmm_free_vm(struct tegra_iovmm_area *vm) { }
+static inline size_t tegra_iovmm_get_max_free(struct tegra_iovmm_client *client)
+{
+	return 0;
+}
+
+static inline void tegra_iovmm_vm_insert_pfn(struct tegra_iovmm_area *area,
+	tegra_iovmm_addr_t vaddr, unsigned long pfn) { }
+
+static inline struct tegra_iovmm_area *tegra_iovmm_find_area_get(
+	struct tegra_iovmm_client *client, tegra_iovmm_addr_t addr)
+{
+	return NULL;
+}
+
+static inline struct tegra_iovmm_area *tegra_iovmm_area_get(
+	struct tegra_iovmm_area *vm)
+{
+	return NULL;
+}
+
+static inline void tegra_iovmm_area_put(struct tegra_iovmm_area *vm) { }
+
+static inline int tegra_iovmm_domain_init(struct tegra_iovmm_domain *domain,
+	struct tegra_iovmm_device *dev, tegra_iovmm_addr_t start,
+	tegra_iovmm_addr_t end)
+{
+	return 0;
+}
+
+static inline int tegra_iovmm_register(struct tegra_iovmm_device *dev)
+{
+	return 0;
+}
+
+static inline int tegra_iovmm_unregister(struct tegra_iovmm_device *dev)
+{
+	return 0;
+}
+
+static inline int tegra_iovmm_suspend(void)
+{
+	return 0;
+}
+
+static inline void tegra_iovmm_resume(void) { }
+#endif /* CONFIG_TEGRA_IOVMM */
+
+
+#endif
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 5414253..487d1ee 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -131,4 +131,10 @@ config OMAP_IOMMU_DEBUG
 
          Say N unless you know you need this.
 
+
+# Tegra IOMMU support
+
+config TEGRA_IOVMM
+	bool
+
 endif # IOMMU_SUPPORT
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 2f44487..365eefb 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -7,3 +7,4 @@ obj-$(CONFIG_IRQ_REMAP) += intr_remapping.o
 obj-$(CONFIG_OMAP_IOMMU) += omap-iommu.o
 obj-$(CONFIG_OMAP_IOVMM) += omap-iovmm.o
 obj-$(CONFIG_OMAP_IOMMU_DEBUG) += omap-iommu-debug.o
+obj-$(CONFIG_TEGRA_IOVMM) += tegra-iovmm.o
diff --git a/drivers/iommu/tegra-iovmm.c b/drivers/iommu/tegra-iovmm.c
new file mode 100644
index 0000000..0f2d996
--- /dev/null
+++ b/drivers/iommu/tegra-iovmm.c
@@ -0,0 +1,936 @@
+/*
+ * Tegra I/O VM manager
+ *
+ * Copyright (c) 2010-2011, NVIDIA Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/proc_fs.h>
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/syscore_ops.h>
+
+#include <mach/iovmm.h>
+
+/*
+ * after the best-fit block is located, the remaining pages not needed
+ * for the allocation will be split into a new free block if the
+ * number of remaining pages is >= MIN_SPLIT_PAGE.
+ */
+#define MIN_SPLIT_PAGE		4
+#define MIN_SPLIT_BYTES(_d)	(MIN_SPLIT_PAGE << (_d)->dev->pgsize_bits)
+#define NO_SPLIT(m)		((m) < MIN_SPLIT_BYTES(domain))
+#define DO_SPLIT(m)		((m) >= MIN_SPLIT_BYTES(domain))
+
+#define iovmm_start(_b)		((_b)->vm_area.iovm_start)
+#define iovmm_length(_b)	((_b)->vm_area.iovm_length)
+#define iovmm_end(_b)		(iovmm_start(_b) + iovmm_length(_b))
+
+/* flags for the block */
+#define BK_free		0 /* indicates free mappings */
+#define BK_map_dirty	1 /* used by demand-loaded mappings */
+
+/* flags for the client */
+#define CL_locked	0
+
+/* flags for the domain */
+#define DM_map_dirty	0
+
+struct tegra_iovmm_block {
+	struct tegra_iovmm_area vm_area;
+	tegra_iovmm_addr_t	start;
+	size_t			length;
+	atomic_t		ref;
+	unsigned long		flags;
+	unsigned long		poison;
+	struct rb_node		free_node;
+	struct rb_node		all_node;
+};
+
+struct iovmm_share_group {
+	const char			*name;
+	struct tegra_iovmm_domain	*domain;
+	struct list_head		client_list;
+	struct list_head		group_list;
+	spinlock_t			lock; /* for client_list */
+};
+
+static LIST_HEAD(iovmm_devices);
+static LIST_HEAD(iovmm_groups);
+static DEFINE_MUTEX(iovmm_group_list_lock);
+static struct kmem_cache *iovmm_cache;
+
+#define SIMALIGN(b, a)	(((b)->start % (a)) ? ((a) - ((b)->start % (a))) : 0)
+
+size_t tegra_iovmm_get_max_free(struct tegra_iovmm_client *client)
+{
+	struct rb_node *n;
+	struct tegra_iovmm_block *b;
+	struct tegra_iovmm_domain *domain = client->domain;
+	tegra_iovmm_addr_t max_free = 0;
+
+	spin_lock(&domain->block_lock);
+	n = rb_first(&domain->all_blocks);
+	while (n) {
+		b = rb_entry(n, struct tegra_iovmm_block, all_node);
+		n = rb_next(n);
+		if (test_bit(BK_free, &b->flags)) {
+			max_free = max_t(tegra_iovmm_addr_t,
+				max_free, iovmm_length(b));
+		}
+	}
+	spin_unlock(&domain->block_lock);
+	return max_free;
+}
+
+
+static void tegra_iovmm_block_stats(struct tegra_iovmm_domain *domain,
+	unsigned int *num_blocks, unsigned int *num_free,
+	tegra_iovmm_addr_t *total, size_t *total_free, size_t *max_free)
+{
+	struct rb_node *n;
+	struct tegra_iovmm_block *b;
+
+	*num_blocks = 0;
+	*num_free = 0;
+	*total = 0;
+	*total_free = 0;
+	*max_free = 0;
+
+	spin_lock(&domain->block_lock);
+	n = rb_first(&domain->all_blocks);
+	while (n) {
+		b = rb_entry(n, struct tegra_iovmm_block, all_node);
+		n = rb_next(n);
+		(*num_blocks)++;
+		*total += b->length;
+		if (test_bit(BK_free, &b->flags)) {
+			(*num_free)++;
+			*total_free += b->length;
+			*max_free = max_t(size_t, *max_free, b->length);
+		}
+	}
+	spin_unlock(&domain->block_lock);
+}
+
+static int tegra_iovmm_read_proc(char *page, char **start, off_t off,
+	int count, int *eof, void *data)
+{
+	struct iovmm_share_group *grp;
+	size_t max_free, total_free, total;
+	unsigned int num, num_free;
+
+	int len = 0;
+
+	mutex_lock(&iovmm_group_list_lock);
+	len += snprintf(page + len, count - len, "\ngroups\n");
+	if (list_empty(&iovmm_groups))
+		len += snprintf(page + len, count - len, "\t<empty>\n");
+	else {
+		list_for_each_entry(grp, &iovmm_groups, group_list) {
+			len += snprintf(page + len, count - len,
+					"\t%s (device: %s)\n",
+				(grp->name) ? grp->name : "<unnamed>",
+				grp->domain->dev->name);
+			tegra_iovmm_block_stats(grp->domain, &num,
+				&num_free, &total, &total_free, &max_free);
+			total >>= 10;
+			total_free >>= 10;
+			max_free >>= 10;
+			len += snprintf(page + len, count - len,
+				"\t\tsize: %uKiB free: %uKiB "
+				"largest: %uKiB (%u free / %u total blocks)\n",
+				total, total_free, max_free, num_free, num);
+		}
+	}
+	mutex_unlock(&iovmm_group_list_lock);
+
+	*eof = 1;
+	return len;
+}
+
+static void iovmm_block_put(struct tegra_iovmm_block *b)
+{
+	BUG_ON(b->poison);
+	BUG_ON(atomic_read(&b->ref) == 0);
+	if (!atomic_dec_return(&b->ref)) {
+		b->poison = 0xa5a5a5a5;
+		kmem_cache_free(iovmm_cache, b);
+	}
+}
+
+static void iovmm_free_block(struct tegra_iovmm_domain *domain,
+	struct tegra_iovmm_block *block)
+{
+	struct tegra_iovmm_block *pred = NULL; /* address-order predecessor */
+	struct tegra_iovmm_block *succ = NULL; /* address-order successor */
+	struct rb_node **p;
+	struct rb_node *parent = NULL, *temp;
+	int pred_free = 0, succ_free = 0;
+
+	iovmm_block_put(block);
+
+	spin_lock(&domain->block_lock);
+	temp = rb_prev(&block->all_node);
+	if (temp)
+		pred = rb_entry(temp, struct tegra_iovmm_block, all_node);
+	temp = rb_next(&block->all_node);
+	if (temp)
+		succ = rb_entry(temp, struct tegra_iovmm_block, all_node);
+
+	if (pred)
+		pred_free = test_bit(BK_free, &pred->flags);
+	if (succ)
+		succ_free = test_bit(BK_free, &succ->flags);
+
+	if (pred_free && succ_free) {
+		pred->length += block->length;
+		pred->length += succ->length;
+		rb_erase(&block->all_node, &domain->all_blocks);
+		rb_erase(&succ->all_node, &domain->all_blocks);
+		rb_erase(&succ->free_node, &domain->free_blocks);
+		rb_erase(&pred->free_node, &domain->free_blocks);
+		iovmm_block_put(block);
+		iovmm_block_put(succ);
+		block = pred;
+	} else if (pred_free) {
+		pred->length += block->length;
+		rb_erase(&block->all_node, &domain->all_blocks);
+		rb_erase(&pred->free_node, &domain->free_blocks);
+		iovmm_block_put(block);
+		block = pred;
+	} else if (succ_free) {
+		block->length += succ->length;
+		rb_erase(&succ->all_node, &domain->all_blocks);
+		rb_erase(&succ->free_node, &domain->free_blocks);
+		iovmm_block_put(succ);
+	}
+
+	p = &domain->free_blocks.rb_node;
+	while (*p) {
+		struct tegra_iovmm_block *b;
+		parent = *p;
+		b = rb_entry(parent, struct tegra_iovmm_block, free_node);
+		if (block->length >= b->length)
+			p = &parent->rb_right;
+		else
+			p = &parent->rb_left;
+	}
+	rb_link_node(&block->free_node, parent, p);
+	rb_insert_color(&block->free_node, &domain->free_blocks);
+	set_bit(BK_free, &block->flags);
+	spin_unlock(&domain->block_lock);
+}
+
+/* if the best-fit block is larger than the requested size, a remainder
+ * block will be created and inserted into the free list in its place.
+ * since all free blocks are stored in two trees the new block needs to be
+ * linked into both. */
+static struct tegra_iovmm_block *iovmm_split_free_block(
+	struct tegra_iovmm_domain *domain,
+	struct tegra_iovmm_block *block, unsigned long size)
+{
+	struct rb_node **p;
+	struct rb_node *parent = NULL;
+	struct tegra_iovmm_block *rem;
+	struct tegra_iovmm_block *b;
+
+	rem = kmem_cache_zalloc(iovmm_cache, GFP_KERNEL);
+	if (!rem)
+		return NULL;
+
+	spin_lock(&domain->block_lock);
+	p = &domain->free_blocks.rb_node;
+
+	rem->start  = block->start + size;
+	rem->length = block->length - size;
+	atomic_set(&rem->ref, 1);
+	block->length = size;
+
+	while (*p) {
+		parent = *p;
+		b = rb_entry(parent, struct tegra_iovmm_block, free_node);
+		if (rem->length >= b->length)
+			p = &parent->rb_right;
+		else
+			p = &parent->rb_left;
+	}
+	set_bit(BK_free, &rem->flags);
+	rb_link_node(&rem->free_node, parent, p);
+	rb_insert_color(&rem->free_node, &domain->free_blocks);
+
+	p = &domain->all_blocks.rb_node;
+	parent = NULL;
+	while (*p) {
+		parent = *p;
+		b = rb_entry(parent, struct tegra_iovmm_block, all_node);
+		if (rem->start >= b->start)
+			p = &parent->rb_right;
+		else
+			p = &parent->rb_left;
+	}
+	rb_link_node(&rem->all_node, parent, p);
+	rb_insert_color(&rem->all_node, &domain->all_blocks);
+
+	return rem;
+}
+
+static int iovmm_block_splitting;
+static struct tegra_iovmm_block *iovmm_alloc_block(
+	struct tegra_iovmm_domain *domain, size_t size, size_t align)
+{
+	struct rb_node *n;
+	struct tegra_iovmm_block *b, *best;
+	size_t simalign;
+	unsigned long page_size = 1 << domain->dev->pgsize_bits;
+
+	BUG_ON(!size);
+
+	size = round_up(size, page_size);
+	align = round_up(align, page_size);
+	for (;;) {
+		spin_lock(&domain->block_lock);
+		if (!iovmm_block_splitting)
+			break;
+		spin_unlock(&domain->block_lock);
+		schedule();
+	}
+	n = domain->free_blocks.rb_node;
+	best = NULL;
+	while (n) {
+		tegra_iovmm_addr_t aligned_start, block_ceil;
+
+		b = rb_entry(n, struct tegra_iovmm_block, free_node);
+		simalign = SIMALIGN(b, align);
+		aligned_start = b->start + simalign;
+		block_ceil = b->start + b->length;
+
+		if (block_ceil >= aligned_start + size) {
+			/* Block has enough size */
+			best = b;
+			if (NO_SPLIT(simalign) &&
+				NO_SPLIT(block_ceil - (aligned_start + size)))
+				break;
+			n = n->rb_left;
+		} else {
+			n = n->rb_right;
+		}
+	}
+	if (!best) {
+		spin_unlock(&domain->block_lock);
+		return NULL;
+	}
+
+	simalign = SIMALIGN(best, align);
+	if (DO_SPLIT(simalign)) {
+		iovmm_block_splitting = 1;
+		spin_unlock(&domain->block_lock);
+
+		/* Split off misalignment */
+		b = best;
+		best = iovmm_split_free_block(domain, b, simalign);
+		if (best)
+			simalign = 0;
+		else
+			best = b;
+	}
+
+	/* Unfree designed block */
+	rb_erase(&best->free_node, &domain->free_blocks);
+	clear_bit(BK_free, &best->flags);
+	atomic_inc(&best->ref);
+
+	iovmm_start(best) = best->start + simalign;
+	iovmm_length(best) = size;
+
+	if (DO_SPLIT((best->start + best->length) - iovmm_end(best))) {
+		iovmm_block_splitting = 1;
+		spin_unlock(&domain->block_lock);
+
+		/* Split off excess */
+		(void)iovmm_split_free_block(domain, best, size + simalign);
+	}
+
+	iovmm_block_splitting = 0;
+	spin_unlock(&domain->block_lock);
+
+	return best;
+}
+
+static struct tegra_iovmm_block *iovmm_allocate_vm(
+	struct tegra_iovmm_domain *domain, size_t size,
+	size_t align, unsigned long iovm_start)
+{
+	struct rb_node *n;
+	struct tegra_iovmm_block *b, *best;
+	unsigned long page_size = 1 << domain->dev->pgsize_bits;
+
+	BUG_ON(iovm_start % align);
+	BUG_ON(!size);
+
+	size = round_up(size, page_size);
+	for (;;) {
+		spin_lock(&domain->block_lock);
+		if (!iovmm_block_splitting)
+			break;
+		spin_unlock(&domain->block_lock);
+		schedule();
+	}
+
+	n = rb_first(&domain->free_blocks);
+	best = NULL;
+	while (n) {
+		b = rb_entry(n, struct tegra_iovmm_block, free_node);
+		if ((b->start <= iovm_start) &&
+		     (b->start + b->length) >= (iovm_start + size)) {
+			best = b;
+			break;
+		}
+		n = rb_next(n);
+	}
+
+	if (!best)
+		goto fail;
+
+	/* split the mem before iovm_start. */
+	if (DO_SPLIT(iovm_start - best->start)) {
+		iovmm_block_splitting = 1;
+		spin_unlock(&domain->block_lock);
+		best = iovmm_split_free_block(domain, best,
+			(iovm_start - best->start));
+	}
+	if (!best)
+		goto fail;
+
+	/* remove the desired block from free list. */
+	rb_erase(&best->free_node, &domain->free_blocks);
+	clear_bit(BK_free, &best->flags);
+	atomic_inc(&best->ref);
+
+	iovmm_start(best) = iovm_start;
+	iovmm_length(best) = size;
+
+	BUG_ON(best->start > iovmm_start(best));
+	BUG_ON((best->start + best->length) < iovmm_end(best));
+	/* split the mem after iovm_start+size. */
+	if (DO_SPLIT(best->start + best->length - iovmm_end(best))) {
+		iovmm_block_splitting = 1;
+		spin_unlock(&domain->block_lock);
+		(void)iovmm_split_free_block(domain, best,
+			(iovmm_start(best) - best->start + size));
+	}
+fail:
+	iovmm_block_splitting = 0;
+	spin_unlock(&domain->block_lock);
+	return best;
+}
+
+int tegra_iovmm_domain_init(struct tegra_iovmm_domain *domain,
+	struct tegra_iovmm_device *dev, tegra_iovmm_addr_t start,
+	tegra_iovmm_addr_t end)
+{
+	struct tegra_iovmm_block *b;
+	unsigned long page_size = 1 << dev->pgsize_bits;
+
+	b = kmem_cache_zalloc(iovmm_cache, GFP_KERNEL);
+	if (!b)
+		return -ENOMEM;
+
+	domain->dev = dev;
+
+	atomic_set(&domain->clients, 0);
+	atomic_set(&domain->locks, 0);
+	atomic_set(&b->ref, 1);
+	spin_lock_init(&domain->block_lock);
+	init_rwsem(&domain->map_lock);
+	init_waitqueue_head(&domain->delay_lock);
+
+	b->start  = round_up(start, page_size);
+	b->length = round_down(end, page_size) - b->start;
+
+	set_bit(BK_free, &b->flags);
+	rb_link_node(&b->free_node, NULL, &domain->free_blocks.rb_node);
+	rb_insert_color(&b->free_node, &domain->free_blocks);
+	rb_link_node(&b->all_node, NULL, &domain->all_blocks.rb_node);
+	rb_insert_color(&b->all_node, &domain->all_blocks);
+
+	return 0;
+}
+
+/* If iovm_start != 0, tries to allocate specified iova block if it is free.
+ * if it is not free, it fails.
+ */
+struct tegra_iovmm_area *tegra_iovmm_create_vm(
+	struct tegra_iovmm_client *client, struct tegra_iovmm_area_ops *ops,
+	size_t size, size_t align, pgprot_t pgprot, unsigned long iovm_start)
+{
+	struct tegra_iovmm_block *b;
+	struct tegra_iovmm_domain *domain;
+
+	if (!client)
+		return NULL;
+
+	domain = client->domain;
+
+	if (iovm_start)
+		b = iovmm_allocate_vm(domain, size, align, iovm_start);
+	else
+		b = iovmm_alloc_block(domain, size, align);
+	if (!b)
+		return NULL;
+
+	b->vm_area.domain = domain;
+	b->vm_area.pgprot = pgprot;
+	b->vm_area.ops = ops;
+
+	down_read(&b->vm_area.domain->map_lock);
+	if (ops && !test_bit(CL_locked, &client->flags)) {
+		set_bit(BK_map_dirty, &b->flags);
+		set_bit(DM_map_dirty, &client->domain->flags);
+	} else if (ops) {
+		if (domain->dev->ops->map(domain, &b->vm_area))
+			pr_err("%s failed to map locked domain\n", __func__);
+	}
+	up_read(&b->vm_area.domain->map_lock);
+
+	return &b->vm_area;
+}
+
+void tegra_iovmm_vm_insert_pfn(struct tegra_iovmm_area *vm,
+	tegra_iovmm_addr_t vaddr, unsigned long pfn)
+{
+	struct tegra_iovmm_domain *domain = vm->domain;
+	BUG_ON(vaddr & ((1<<domain->dev->pgsize_bits)-1));
+	BUG_ON(vaddr >= vm->iovm_start + vm->iovm_length);
+	BUG_ON(vaddr < vm->iovm_start);
+	BUG_ON(vm->ops);
+
+	domain->dev->ops->map_pfn(domain, vm, vaddr, pfn);
+}
+
+void tegra_iovmm_zap_vm(struct tegra_iovmm_area *vm)
+{
+	struct tegra_iovmm_block *b;
+	struct tegra_iovmm_domain *domain;
+
+	b = container_of(vm, struct tegra_iovmm_block, vm_area);
+	domain = vm->domain;
+	/*
+	 * if the vm area mapping was deferred, don't unmap it since
+	 * the memory for the page tables it uses may not be allocated
+	 */
+	down_read(&domain->map_lock);
+	if (!test_and_clear_bit(BK_map_dirty, &b->flags))
+		domain->dev->ops->unmap(domain, vm, false);
+	up_read(&domain->map_lock);
+}
+
+void tegra_iovmm_unzap_vm(struct tegra_iovmm_area *vm)
+{
+	struct tegra_iovmm_block *b;
+	struct tegra_iovmm_domain *domain;
+
+	b = container_of(vm, struct tegra_iovmm_block, vm_area);
+	domain = vm->domain;
+	if (!vm->ops)
+		return;
+
+	down_read(&domain->map_lock);
+	if (vm->ops) {
+		if (atomic_read(&domain->locks))
+			domain->dev->ops->map(domain, vm);
+		else {
+			set_bit(BK_map_dirty, &b->flags);
+			set_bit(DM_map_dirty, &domain->flags);
+		}
+	}
+	up_read(&domain->map_lock);
+}
+
+void tegra_iovmm_free_vm(struct tegra_iovmm_area *vm)
+{
+	struct tegra_iovmm_block *b;
+	struct tegra_iovmm_domain *domain;
+
+	if (!vm)
+		return;
+
+	b = container_of(vm, struct tegra_iovmm_block, vm_area);
+	domain = vm->domain;
+	down_read(&domain->map_lock);
+	if (!test_and_clear_bit(BK_map_dirty, &b->flags))
+		domain->dev->ops->unmap(domain, vm, true);
+	iovmm_free_block(domain, b);
+	up_read(&domain->map_lock);
+}
+
+struct tegra_iovmm_area *tegra_iovmm_area_get(struct tegra_iovmm_area *vm)
+{
+	struct tegra_iovmm_block *b;
+
+	BUG_ON(!vm);
+	b = container_of(vm, struct tegra_iovmm_block, vm_area);
+
+	atomic_inc(&b->ref);
+	return &b->vm_area;
+}
+
+void tegra_iovmm_area_put(struct tegra_iovmm_area *vm)
+{
+	struct tegra_iovmm_block *b;
+	BUG_ON(!vm);
+	b = container_of(vm, struct tegra_iovmm_block, vm_area);
+	iovmm_block_put(b);
+}
+
+struct tegra_iovmm_area *tegra_iovmm_find_area_get(
+	struct tegra_iovmm_client *client, tegra_iovmm_addr_t addr)
+{
+	struct rb_node *n;
+	struct tegra_iovmm_block *b = NULL;
+
+	if (!client)
+		return NULL;
+
+	spin_lock(&client->domain->block_lock);
+	n = client->domain->all_blocks.rb_node;
+
+	while (n) {
+		b = rb_entry(n, struct tegra_iovmm_block, all_node);
+		if (iovmm_start(b) <= addr && addr <= iovmm_end(b)) {
+			if (test_bit(BK_free, &b->flags))
+				b = NULL;
+			break;
+		}
+		if (addr > iovmm_start(b))
+			n = n->rb_right;
+		else
+			n = n->rb_left;
+		b = NULL;
+	}
+	if (b)
+		atomic_inc(&b->ref);
+	spin_unlock(&client->domain->block_lock);
+	if (!b)
+		return NULL;
+	return &b->vm_area;
+}
+
+static int _iovmm_client_lock(struct tegra_iovmm_client *client)
+{
+	struct tegra_iovmm_device *dev;
+	struct tegra_iovmm_domain *domain;
+	int v;
+
+	if (unlikely(!client))
+		return -ENODEV;
+
+	if (unlikely(test_bit(CL_locked, &client->flags))) {
+		pr_err("attempting to relock client %s\n", client->name);
+		return 0;
+	}
+
+	domain = client->domain;
+	dev = domain->dev;
+	down_write(&domain->map_lock);
+	v = atomic_inc_return(&domain->locks);
+	/* if the device doesn't export the lock_domain function, the device
+	 * must guarantee that any valid domain will be locked. */
+	if (v == 1 && dev->ops->lock_domain) {
+		if (dev->ops->lock_domain(domain, client)) {
+			atomic_dec(&domain->locks);
+			up_write(&domain->map_lock);
+			return -EAGAIN;
+		}
+	}
+	if (test_and_clear_bit(DM_map_dirty, &domain->flags)) {
+		struct rb_node *n;
+		struct tegra_iovmm_block *b;
+
+		spin_lock(&domain->block_lock);
+		n = rb_first(&domain->all_blocks);
+		while (n) {
+			b = rb_entry(n, struct tegra_iovmm_block, all_node);
+			n = rb_next(n);
+			if (test_bit(BK_free, &b->flags))
+				continue;
+
+			if (test_and_clear_bit(BK_map_dirty, &b->flags)) {
+				if (!b->vm_area.ops) {
+					pr_err("%s: "
+					       "vm_area ops must exist for lazy maps\n",
+					       __func__);
+					continue;
+				}
+				dev->ops->map(domain, &b->vm_area);
+			}
+		}
+	}
+	set_bit(CL_locked, &client->flags);
+	up_write(&domain->map_lock);
+	return 0;
+}
+
+int tegra_iovmm_client_trylock(struct tegra_iovmm_client *client)
+{
+	return _iovmm_client_lock(client);
+}
+
+int tegra_iovmm_client_lock(struct tegra_iovmm_client *client)
+{
+	int ret;
+
+	if (!client)
+		return -ENODEV;
+
+	ret = wait_event_interruptible(client->domain->delay_lock,
+		_iovmm_client_lock(client) != -EAGAIN);
+
+	if (ret == -ERESTARTSYS)
+		return -EINTR;
+
+	return ret;
+}
+
+void tegra_iovmm_client_unlock(struct tegra_iovmm_client *client)
+{
+	struct tegra_iovmm_device *dev;
+	struct tegra_iovmm_domain *domain;
+	int do_wake = 0;
+
+	if (!client)
+		return;
+
+	if (!test_and_clear_bit(CL_locked, &client->flags)) {
+		pr_err("unlocking unlocked client %s\n", client->name);
+		return;
+	}
+
+	domain = client->domain;
+	dev = domain->dev;
+	down_write(&domain->map_lock);
+	if (!atomic_dec_return(&domain->locks)) {
+		if (dev->ops->unlock_domain)
+			dev->ops->unlock_domain(domain, client);
+		do_wake = 1;
+	}
+	up_write(&domain->map_lock);
+	if (do_wake)
+		wake_up(&domain->delay_lock);
+}
+
+size_t tegra_iovmm_get_vm_size(struct tegra_iovmm_client *client)
+{
+	struct tegra_iovmm_domain *domain;
+	struct rb_node *n;
+	struct tegra_iovmm_block *b;
+	size_t size = 0;
+
+	if (!client)
+		return 0;
+
+	domain = client->domain;
+
+	spin_lock(&domain->block_lock);
+	n = rb_first(&domain->all_blocks);
+	while (n) {
+		b = rb_entry(n, struct tegra_iovmm_block, all_node);
+		n = rb_next(n);
+		size += b->length;
+	}
+	spin_unlock(&domain->block_lock);
+
+	return size;
+}
+
+void tegra_iovmm_free_client(struct tegra_iovmm_client *client)
+{
+	struct tegra_iovmm_device *dev;
+	struct tegra_iovmm_domain *domain;
+
+	if (!client)
+		return;
+
+	BUG_ON(!client->domain || !client->domain->dev);
+
+	domain = client->domain;
+	dev = domain->dev;
+
+	if (test_and_clear_bit(CL_locked, &client->flags)) {
+		pr_err("freeing locked client %s\n", client->name);
+		if (!atomic_dec_return(&domain->locks)) {
+			down_write(&domain->map_lock);
+			if (dev->ops->unlock_domain)
+				dev->ops->unlock_domain(domain, client);
+			up_write(&domain->map_lock);
+			wake_up(&domain->delay_lock);
+		}
+	}
+	mutex_lock(&iovmm_group_list_lock);
+	if (!atomic_dec_return(&domain->clients))
+		if (dev->ops->free_domain)
+			dev->ops->free_domain(domain, client);
+	list_del(&client->list);
+	if (list_empty(&client->group->client_list)) {
+		list_del(&client->group->group_list);
+		kfree(client->group->name);
+		kfree(client->group);
+	}
+	kfree(client->name);
+	kfree(client);
+	mutex_unlock(&iovmm_group_list_lock);
+}
+
+struct tegra_iovmm_client *tegra_iovmm_alloc_client(const char *name,
+	const char *share_group, struct miscdevice *misc_dev)
+{
+	struct tegra_iovmm_client *c = kzalloc(sizeof(*c), GFP_KERNEL);
+	struct iovmm_share_group *grp = NULL;
+	struct tegra_iovmm_device *dev;
+
+	if (!c)
+		return NULL;
+	c->name = kstrdup(name, GFP_KERNEL);
+	if (!c->name)
+		goto fail;
+	c->misc_dev = misc_dev;
+
+	mutex_lock(&iovmm_group_list_lock);
+	if (share_group) {
+		list_for_each_entry(grp, &iovmm_groups, group_list) {
+			if (grp->name && !strcmp(grp->name, share_group))
+				break;
+		}
+	}
+	if (!grp || strcmp(grp->name, share_group)) {
+		grp = kzalloc(sizeof(*grp), GFP_KERNEL);
+		if (!grp)
+			goto fail_lock;
+		grp->name =
+			(share_group) ? kstrdup(share_group, GFP_KERNEL) : NULL;
+		if (share_group && !grp->name) {
+			kfree(grp);
+			goto fail_lock;
+		}
+		list_for_each_entry(dev, &iovmm_devices, list) {
+			grp->domain = dev->ops->alloc_domain(dev, c);
+			if (grp->domain)
+				break;
+		}
+		if (!grp->domain) {
+			pr_err("%s: alloc_domain failed for %s\n",
+				__func__, c->name);
+			dump_stack();
+			kfree(grp->name);
+			kfree(grp);
+			grp = NULL;
+			goto fail_lock;
+		}
+		spin_lock_init(&grp->lock);
+		INIT_LIST_HEAD(&grp->client_list);
+		list_add_tail(&grp->group_list, &iovmm_groups);
+	}
+
+	atomic_inc(&grp->domain->clients);
+	c->group = grp;
+	c->domain = grp->domain;
+	spin_lock(&grp->lock);
+	list_add_tail(&c->list, &grp->client_list);
+	spin_unlock(&grp->lock);
+	mutex_unlock(&iovmm_group_list_lock);
+	return c;
+
+fail_lock:
+	mutex_unlock(&iovmm_group_list_lock);
+fail:
+	if (c)
+		kfree(c->name);
+	kfree(c);
+	return NULL;
+}
+
+int tegra_iovmm_register(struct tegra_iovmm_device *dev)
+{
+	BUG_ON(!dev);
+	mutex_lock(&iovmm_group_list_lock);
+	if (list_empty(&iovmm_devices)) {
+		iovmm_cache = KMEM_CACHE(tegra_iovmm_block, 0);
+		if (!iovmm_cache) {
+			pr_err("%s: failed to make kmem cache\n", __func__);
+			mutex_unlock(&iovmm_group_list_lock);
+			return -ENOMEM;
+		}
+		create_proc_read_entry("iovmminfo", S_IRUGO, NULL,
+			tegra_iovmm_read_proc, NULL);
+	}
+	list_add_tail(&dev->list, &iovmm_devices);
+	mutex_unlock(&iovmm_group_list_lock);
+	pr_info("%s: added %s\n", __func__, dev->name);
+	return 0;
+}
+
+int tegra_iovmm_unregister(struct tegra_iovmm_device *dev)
+{
+	mutex_lock(&iovmm_group_list_lock);
+	list_del(&dev->list);
+	mutex_unlock(&iovmm_group_list_lock);
+	return 0;
+}
+
+static int tegra_iovmm_suspend(void)
+{
+	int rc = 0;
+	struct tegra_iovmm_device *dev;
+
+	list_for_each_entry(dev, &iovmm_devices, list) {
+
+		if (!dev->ops->suspend)
+			continue;
+
+		rc = dev->ops->suspend(dev);
+		if (rc) {
+			pr_err("%s: %s suspend returned %d\n",
+			       __func__, dev->name, rc);
+			return rc;
+		}
+	}
+	return 0;
+}
+
+static void tegra_iovmm_resume(void)
+{
+	struct tegra_iovmm_device *dev;
+
+	list_for_each_entry(dev, &iovmm_devices, list) {
+		if (dev->ops->resume)
+			dev->ops->resume(dev);
+	}
+}
+
+static struct syscore_ops tegra_iovmm_syscore_ops = {
+	.suspend = tegra_iovmm_suspend,
+	.resume = tegra_iovmm_resume,
+};
+
+static __init int tegra_iovmm_syscore_init(void)
+{
+	register_syscore_ops(&tegra_iovmm_syscore_ops);
+	return 0;
+}
+subsys_initcall(tegra_iovmm_syscore_init);
